July 23 – The Great Carrier Reef

Today’s Factismal: The world’s largest artificial reef is an old aircraft carrier sunk off the Florida coast.

Quick! What’s 911 ft long, 150 ft wide, 150 ft tall, and 70 ft under water? It is the USS Oriskany, also known as the Great Carrier Reef and the USS Orisanky. Once an aircraft carrier and the pride of the US Navy, she is now the world’s largest artificial reef and an on-going experiment in how reefs form.

A view through the superstructure of the Great Carrier Reef (Image courtesy MBT Divers)

A view through the superstructure of the Great Carrier Reef
(Image courtesy MBT Divers)

Sinking things to make a reef isn’t a new idea. The Persians did it 3,000 years ago in order to keep pirates out of their port. The Japanese did it 400 years ago in order to grow kelp for sushi. And the Americans did it two centuries ago in order to get more fish. What is new is using massive structures such as aircraft carriers, automobiles, and even bridges, as the base of the reef.

reefOnce sunken, the structure does three things. First, it deflects the bottom currents, sending them and their nutrient-rich water up to the sunny surface where they feed plankton. That then leads to a population explosion of the tiny little krill and other critters who then provide a banquet for small fish which are eaten by bigger fish.

Second, the structure provides hidey holes for the fish. Groupers, eels, and barracuda lurk in the shadows, hoping for a tasty morsel to swim by, while sardines and minnows span in the crevices, seeking safe places to hide their eggs. All told, reefs provide a habitat for about 25% of the world’s species of fish.

The third thing that artificial reefs do is provide a framework for coral, sponges, and other reef-building animals to live on. By giving the baby coral polyps many different places to rest at different depths in the water, the artificial reefs are able to bootstrap the reef building process. Instead of taking centuries for the basal reef builders to provide a substrate that is then taken over by the secondary reef critters, an artificial reef can have it all happening simultaneously.

If you’d like to learn more about coral reefs and how they form oases in the oceans, then head on over to the Coral Reef Monitoring Program!

July 22 – Hole In One

Today’s Factismal: An accidental gunshot to Alexis St. Martin’s stomach led to the discovery of how we digest our food.

How would you like to get paid to eat food? Though it might sound like a dream job at first, you probably wouldn’t enjoy the interview: in order to get the job, Alexis St. Martin was accidentally shot in the stomach! As a young fur trapper, Alexis traveled all over Canada looking for beaver (which was much in demand at the time). While he was visiting the Mackinac Island trading post on June 5, 1822, the musket of one of the other trappers accidentally went off and hit poor Alexis in the stomach.

The US Army surgeon by the name of William Beaumont at the nearby fort took care of Alexis and kept him alive until the wound healed. But, instead of healing over, the edges of his stomach healed to the edges of his skin creating a hole into his innards. Beaumont was no dummy; he realized that this provided a unique opportunity to find out what happened to food in the stomach and to increase our understanding of how digestion works. At the time about all that was known about digestion was that food went in one end and used food came out the other.

For the next eleven years, Beaumont kept Alexis as a servant. Though Alexis chopped wood, carried water, and did the other things expected of a servant, his main job was to lie still as the doctor dangled food on a string in his stomach. By observing the changes in the food and recording Alexis’ changes while the food was being digested, Beaumont was able to tease out the digestive processes that happened in the stomach. Beaumont published the results in 1838 in a tome called Experiments and Observations on the Gastric Juice, and the Physiology of Digestion; it is still used by medical students today.

If you’d like to help advance medicine but don’t like the idea of getting shot in the stomach, there is an easier way to make a significant contribution. The folks over at Cell Slider need sharp-eyed citizen scientists (Hey! that’s you!) to look over the results of experiments to cure cancer. All you have to do is examine images and determine if the cells are healthy or not (it is easier than it sounds). If you’d like to do your part, then head on over to

July 21 – Go Away!

Today’s factismal: It once rained for 45 days straight in Texas.

One of life’s little ironies is that sometimes you get more than you asked for. That was the situation in Texas in 2007. For three years, the state had been in a steadily worsening drought. Lakes and reservoirs were empty. Water rationing was in effect across the state. Wildfires had turned two million acres of land into the world’s largest impromptu barbeque. By August of 2006, more than 90% of Texas had slipped into drought; for three-quarters of the state, the drought was exceptional or severe. All told, the dry weather caused more than $4 billion in damages. Texans were desperate and praying for rain.

And in late March 2007, Texans thought that their prayers had been answered. Texas and Oklahoma were nestled between two parallel high pressure belts in the atmosphere that kept a low pressure zone centered on them.  A continual stream of moist air from the Gulf of Mexico made its way up to the low pressure zone and fed rain clouds. And so the rains came in and stayed. Every day, for 45 days, it rained. Some days only saw a light drizzle. But others had rainfalls of an inch or more. Lakes and reservoirs refilled. The ground was soaked and saturated with water. Flood damage took the place of drought. And still the rain fell.

A radar image of the storm that ended the 2007 Texas floods (Image courtesy USWS)

A radar image of the storm that ended the 2007 Texas floods
(Image courtesy USWS)

The rainfall continued for 45 days and nights. And when it finally stopped, it did so with a bang. On June 27, 2007, a massive rainstorm hit central Texas. Over just six hours, more than 18 inches of rain fell at Marble Falls – nearly as much as had fallen in the month previous! That sudden “rain bomb” caused flash floods that took the lives of thirteen people and did millions of dollars in damage. Streams and rivers had record flow levels. Flash flooding was everywhere. By the time it was over, Texas had suffered it’s ninth worst flood.

An view from above teh floodwaters (Image courtesy Tony Gutierrez/Associated Press)

An view from above teh floodwaters
(Image courtesy Tony Gutierrez/Associated Press)

But the most amazing thing about the flood was that it was predicted and people were warned. Thanks to data collected by the National Weather Service and by hundreds of citizen scientists in Texas, forecasters had known that a major storm was coming since the day before and had warned the public about the danger. Thanks to that warning, what could have been a major disaster was just a huge one. If you’d like to help the National Weather Service prevent the next big disaster, why not join CoCoRAHS? This group hosts automatic rain gauges in their backyards and reports the data to the NWS, where it gets added into models predicting unusual rain events like the Marble Falls rain bomb. To take part, flow on over to:

July 20 – Call Of The Wildebeest

Today’s Factismal: Every year, over 1,200,000 wildebeest move through the Serengeti during the Great Migration.

One of the world’s most amazing places stretches from northeast Tanzania to southeast Kenya. Known as the Serengeti (Masai for “Endless Plains”), this hilly region is home to 500 different species of birds, 70 different species of large mammals (including the famed “big five“), and countless different species of plants. But what is perhaps most amazing about the Serengeti is the annual wildebeest migration.

Wildebeest on the plains (My camera)

Wildebeest on the plains
(My camera)

Over the course of the year, the more than 1.2 million wildebeest that call the Serengeti home move from the short grass plains where the females all give birth within a three week period to the river region where they shelter from the summer drought and back again. As they move from place to place, their hooves sound like thunder and their coats darken the landscape. It is the world’s largest mass migration of mammals.

Walk a little, graze a litte (My camera)

Walk a little, graze a litte
(My camera)

If you’d like to see the migration happen, then you have two choices. Either you can fly to Africa to watch it in person, or you can join the Wildebeest Watch team and look at the wildebeest and other animals as they pass by trap cameras. Classify what you see and you’ll be taking part in another great migration – that of data from the files to the minds of great scientists.

July 19 – Heart of Brightness

Back in 1979, before the Voyager 1 probe flew by Jupiter and its moon Io, everyone expected to see a dull, dead moon with lots and lots of impact craters and no real personality. And then the images came in, showing the most volcanically active body in the Solar System; heck, Voyager even got to see a volcano erupting! Thanks to that new information, everything that we thought we knew about Io went out the window and the planetologists spent the next few years happily deciphering the why of Io’s volcanism.

Pluto's two smallest moons are not quite the "footballs" some claimed (Image courtesy NASA)

Pluto’s two smallest moons are not quite the “footballs” some claimed
(Image courtesy NASA)

Back in 2014, before New Horizons visited Pluto, we expected to see a cold, dead world much like Mercury: covered with impact craters and with nothing younger than a billion years or so on its surface. Instead, the New Horizons images have shown us a world almost as young as Earth, with resurfaced plains and mountains of ice. (Of course, not everything that we saw was unexpected; for example, the smaller moons are irregular chunks of rock, tumbling around each other in space.) And it isn’t only Pluto that is suprising us. Charon, too, is younger than expeected and has a wider variety of features than we thought to see.

Charon isn't quite the "dead old moon" that we expected (Image courtesy NASA)

Charon isn’t quite the “dead old moon” that we expected
(Image courtesy NASA)

So what is driving this? Why do Pluto and Charon look so different? One hint comes from the mountains of Norgay Montes (Norgay‘s Mountains); another comes from Sputnik Planum (the Plains of Sputnik). Those mountains tower 1,000 ft or more above the surrounding plains. They are made up of ice (which, to a planetologist means water ice, methane ice, CO2 ice, nitrogen ice, and just about any other ice) and strongly resemble ice bergs caught in a frozen sea. And then there is Sputnik Planum, which looks like a kettle of boiling soup that has been flash-frozen. In both cases, the geology argues that heat was applied to the bottom of Pluto’s crust. For Norgay Montes, enough heat was applied to make the mountains break off and slump into the underlying ices. And for Sputnik Planum, even more heat was applied, melting everything into a uniform swamp.

Two clues to Pluto's paradox (Image courtesy NASA)

Two clues to Pluto’s paradox
(Image courtesy NASA)

But wwhere would that heat come from? We’re not sure yet. Suggestions range from fossil heat left over from when Pluto and Charon formed to a recent massive impact to (my personal favorite) tidal friction just like on Io. Pluto and Charon are more like co-orbiting planets than like a planet and a moon. Charon is nearly 1/8th as massive as Pluto (for comparison, our Moon is just 1.2% of Earth’s mass) and orbits so closely that the two planets are tidally locked; they always show the same face to each other. That situation creates enormous tidal stresses in the crust, which cna create large amounts of heat. Of course, that should mean that the two planets are slowly moving toward each other and should have been destroyed aeons ago. So what keeps them apart? Neptune. Just as Io is kept in place by the gravitational influence of Jupiter’s other moons, Pluto and Chron might get a “spin up” every time that the pair passes by Neptune.

Pluto and Chron, dancing out among the stars (Image courtesy NASA)

Pluto and Chron, dancing out among the stars
(Image courtesy NASA)

Of course, this is all speculation at this point. We won’t know for sure until we’ve sspent more time studying the data. And we won’t know for really sure until we send an orbiter to Pluto (so expect some final results in three or four decades). What we do know for sure right now is that we more than got our money’s worth. The New Horizons probe has gathered enough data to help us redefine how planets form and what a planet is. Now we just have to figure out what it means!

July 18 – Doom From The Sky

Peter and Mary were in her backyard on a sultry summer evening, racing after fireflies.

“Hey! I caught one!” Mary shouted with happiness.

“Ooh! Pretty!” said Peter.

“Thank you!”

“Not your firefly; look up there!”

Following Peter’s outstretched arm, Mary looked up just in time to see the end of a meteor as it blazed across the sky.

“I wonder what makes them glow like that,” she mused. “Do you think that they are radioactive?”

“No; it is probably sunlight reflecting off of them like those noctilucent clouds that Mr. Medes told us about in science class last year.”

“Well, it is nice to know that you paid attention to something that I said,” came a voice from behind them.

“Mr. Medes!” the pair exclaimed.

“What are you doing here?” continued Mary.

“Your mother asked me over to see her new telescope,” he replied. “But it looks as if we won’t need it to see the meteor shower.”

“That’s right; they move too quickly to see in the telescope. But what makes them glow like that?” asked Peter.

“That’s an interesting question,” Mr. Medes said. “To answer it, you’ll need to rub your hands together. What do you think will happen?”

“They’ll make noise,” Mary said promptly.

“They’ll get hot,” said Peter.

“OK, you’ve made your predictions – now find out what the answer is!” commanded Mr. Medes.

Eagerly, the pair began to rub their hands vigorously together.

“Hey! My hands are getting warm!” said Mary.

“We learned about this in Boy Scouts,” said Peter. “When you rub things together, the friction between them makes heat. You can even use it to make fire by rubbing sticks together!”

“That’s right,” said Mr. Medes. “When you rub things together, you are taking one type of energy and turning it into another. You are taking energy of motion”

“Kinetic energy!” interjected Mary.

“That’s right; you are turning kinetic energy into heat energy. You can do the same thing by hitting a piece of metal with a hammer. Do it fast enough and you’ll heat the metal up so much that it glows!”

“But what does that have to do with meteors?” asked Peter.

“Well,” Mr. Medes said, “People used to think that it was the friction of the meteorite racing through the air that made them glow. And it does have some effect; some of the little bits that break off are torn away by friction. But there’s something else that has an even bigger effect. To understand it, you’ll need a basketball and an air pump.”

“I’ve got those in my garage!” Peter exclaimed. He quickly raced next door to get the equipment and handed it to Mr. Medes when he got back.

“Wow! That was quick! You almost started to glow yourself,” Mr. Medes joked. Taking the air pump,he plugged it into the basketball. “I want you both to feel the basketball. Tell me, does it feel warmer or cooler than the air around it?”

Looking puzzled, Peter and Mary put their hands on the basketball.

“They feel about the same,” Mary said.

“Yeah, it feels like everything else out here,” Peter added.

Mr. Medes nodded. “That’s because the air and the basketball are in what scientists call ‘thermal equilibrium’; the ball gains heat from the air about as quickly as it gives heat back. Now what I want you to do is take turns pumping air into the basketball. You’ll need to add fifty pumps each. What do you think will happen?”

“The ball can’t get much bigger,” Peter said. “It is already full of air. So it will be just the same.”

“I don’t know,” Mary replied. “If we are adding more air to the ball, then something has to happen. Maybe it will change temperature?”

“There’s only one way to find out,” Mr. Medes said. “Start pumping!”

What do you think will happen? Do the experiment!










“Ladies first!” Peter said, handing the pump handle to Mary. She started eagerly enough, but soon was huffing and puffing each time she pushed the air pump’s handle down.

“Gosh, this is hard!” Mary said. Finally, she finished her fifty pumps. “Your turn!”

“Stand back and watch what a boy can do!” Peter said. His first few attempts went smoothly enough, but pretty soon he was as out of breath as Mary had been. “Maybe I spoke too soon!”

As soon as Peter had finished adding the air to the basketball, Mr. Medes picked it up and said “look at the ball. Is it any bigger?”

When the two shook their heads “no”, he continued “But add all of that air had to do something. Touch the basketball and let me know what you feel.”

Peter and Mary put their hands on the basketball. After a moment, Peter’s face lit up with understanding.

“The ball is warmer than it was!” he exclaimed. “Adding all of that air made it warmer somehow!”

“That’s right,” Mr. Medes said. “When you added the air, you compressed a lot of stuff into a small space. That meant that the stuff couldn’t move as far without running into something, so it started moving in shorter but faster ways. And that means…”

“That the temperature went up!” Mary exclaimed. “Because temperature is just the motion of the molecules; the faster they move, the hotter they are!”

“That’s close enough for now,” Mr. Medes said. “There are a few differences between temperature and heat, but those only matter to a scientist. Your idea is right, and that’s the important thing. When you compress air, it heats up. And that explains the meteor’s glow.”

“How?” Peter asked. “I still don’t get the connection.”

“Those meteors that you see in the sky are little tiny grains of dust that are moving very, very fast. The slowest of them are moving at 24,000 miles per hour and the fastest are trucking along at 94,000 miles per hour. That is so fast that the air can’t get out of the way as the meteor heads toward Earth. So when the dust grain enters the atmosphere, it compresses the air in front of it.” Mr. Medes pushed one hand with the other to show what he meant. “The air transfers some of that heat to the meteor and that heats up the meteor until it glows. Sometimes the outer skin of the bigger ones melt and little drops fly off as it goes through the atmosphere,”

“Is that what makes the little trails that come off of the meteor as it goes through the sky?” asked Peter.

“Yes. Sometimes the meteor hits the air so hard that it is blasted apart, like the one in Russia. And sometimes the meteor is so big that it makes it all the way to the ground,” Mr. Medes continued. “That makes a crater that we call an astrobleme, or ‘star wound’. You’ve probably heard about the one that hit about 65 million years ago.”

“That’s the one that killed the dinosaurs!” Mary said.

“Well, let’s just say that Chicxulub didn’t do them any favors,” chuckled Mr. Medes. “And it isn’t the only one. There are literally hundreds of astroblemes on Earth, and even more on the Moon. And now that your mother has her telescope set up, let’s take a look at those.”

Smiling, the three turned to look through the telescope at the face of the Moon.



July 14 – Calling All Planets

Today’s factismal: We did it! We have successfully visited all nine classical planets!

In lieu of a regular post today (and since I am too busy watching the newsfeed), here are my previous factismals about Pluto. Enjoy!

The New Horizons probe to Pluto carries a telescope named Ralph and a spectrometer named Alice.

Pluto’s moons are not shaped like footballs.

The Earth has less water than Europa, Pluto, or Titan (to name just three planets).

It would take 5.6 planets the size of Pluto to make one Moon (and 169 to make one Earth).

Eris “the Pluto killer” was discovered almost nine years ago.

And now, since I can’t leave well enough alone, here is a corrected version of NASA’s “family portrait” which incorrectly shows all of the planets as being the same size.

NASA wants you to think that all of the planets are the same size (Image courtesy NASA)

NASA wants you to think that all of the planets are the same size
(Image courtesy NASA)

A "family portrait" with all of the planets shown to scale.

A “family portrait” with all of the planets shown to scale.